Marine propulsion unit



Nov. 8, 1938. H. w. MILLER MARINE PROPULSION UNIT Filed Feb. 17, 1936 2 Sheets-Sheet 1 IN VBN TOR.

HARoldWMiHeR BY ,f'mn fl ATTORNEYS lmllllllllm Nov. 8, 1938. H. w. MILLER MARINE PROPULSION UNIT Filed Feb. 17, 1936 2 Sheets-Sheet 2 HARoidWMiHeR I N VEN TOR.

BY 9%,, (W1

A TTORNEY5 Patented Nov. 8, 1938 UNITED STATES PATENT OFFICE MARINE PROPULSION UNIT Harold W. Miller, Charlevoix, Mich.

Application February 17, 1936, Serial No. 64,286 4 Claims. (01. 115-41) This invention relates to marine propulsion and more particularly to detachable propelling units for water craft of the surface type.

One of the objects of the present invention is to provide a novel detachable propelling unit adapted to be installed in a surface water craft or vessel of any type, including those not originally designed to be self-propelled, such as an ordinary river, lake or ocean barge, or any towboat, thereby rendering such water craft or vessel a self-propelled unit.

Another object of the invention is to provide a novel propelling unit capable of being easily and cheaply installed in any water craft without making any substantial alterations in the hull of such craft, and particularly without providing special wells in the hull, adapters in the stern, grooves in the keel, and similar modifications, thereby providing a propelling unit which can be securely installed in any vessel without requiring permanent changes in the vessel structure or weakening the same, which would unfit the vessel for its original uses.

A still further object of the invention is to provide a novel propelling unit which could be easily removed from the vessel in which it has been installed, without leaving any permanent irreparable modifications in the hull of such vessel.

Still another object is to provide a propelling unit which could be adapted with the aid of simple adjusting means to exert the propelling effort at such a location and in such a direction with respect to the longitudinal axis of the hull of the vessel as to give the best efiiciency of the propeller for the particular type of water craft.

Still another object of the invention is to provide a novel propelling unit which could be easily adjusted to changes occurring in the draft conditions of a vessel, effecting the best efiiciency of propulsion both in full load (deep draft) and in light or no load (shallow draft) conditions of the vessel. I

A still further object is to provide a propelling unit which would permit maximum safe immersion of the propeller when the craft is being operated in shallow waters, in which the immersion: of the propeller would be automatically varied in such shallow waters so as to follow the configuration of the bottom of the water channel, 50 and in which the propeller would be maintained at a safe distance from the bottom.

A still further object is to provide means for automatic raising of the propelling unit when passing over submerged obstacles such as rocks, bars, snags, and the like, thereby efiecting an automatic protection to the propeller in dangerous waters irrespective of whether the vessel is moving ahead or astern, or whether its stem is moving sidewise, as may be the case in maneuvering the vessel.

A still further object is to provide a propelling unit which could be rotated in its operative position through a large predetermined angle, thereby effecting the necessary maneuverability of the vessel.

A still further object of the invention is to provide a detachable propelling unit, the submerged parts of which can be easily raised for inspection or removed for repair irrespective of the load condition of the vessel.

Other objects and advantages of the present invention will appear in the following description and appended claims, reference being had to the accompanying drawings forming a part of this specification, wherein two embodiments of the invention are illustrated. In the drawings, wherein like reference characters designate corresponding parts in the several views,

Fig. 1 is a side elevation of the stern of a vessel in which there is installed a detachable propelling unit embodying the present invention.

Fig. 2 is a top view of the construction shown in Fig. 1.

Fig. 3 is a view similar to that of Fig. 1, showing a. modified structure embodying the invention.

Fig. 4 is a top view of the structure shown in Fig. 3.

Fig. 5 is a perspective view showing the adjustment mechanism of the modified structure.

Before explaining in detail the present invention it is to be understood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawings, since the invention is capable of other embodiments and of being practiced or carried out in various Ways. Also it is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation, and it is not intended to limit the invention claimed herein beyond the requirements of the prior art.

Referring to the drawings, A designates generally a water craft or vessel of any type intended to be converted into a self-propelled craft. The detachable propelling units are designated generally in the preferred and modified structures by the characters B and C, respectively. Referring now to Figs. 1 and 2, the preferred structure comprises a power unit b, which is preferably an electric motor of a suitable type and capacity provided with a reversing mechanism, and a propeller 6 of a screw type which is suspended in said power unit and is driven thereby in a manner well known in the art.

A substantially vertical transmission shaft ismounted in a housing 9 which is journaled in brackets III, II and I2 in such a manner that said housing 9 and consequently the entire power unit B can turn in said brackets I0, I I and I2 through a large predetermined angle, but is restrained from any movement in brackets along its longitudinal axis. The ends Illb, I lb, and IZb of said brackets III, II and I2 are adapted to slide on the substantially vertical portions 20b, 28b of frame members 20, 20. Said frame members 20, 20 are securely fastened to the hull of the vessel as at 20a and 200. A connecting member I3 is provided for the purpose of fastening the brackets I0, II and I2 together, thus making them slide on 20b, 201) as a unit. The downward movement of the connected brackets is limited by stops 22, 22 provided at the lower portions of members 20, 20. The thrust of the propeller 6 is transmitted to the lower bracket I2 and to the frame members 20, 20, which transmit it to the hull of the vessel A. If desired, brackets III, II and I2 may be provided at I017. IIb and I2b with suitable rollers in order to eliminate friction incident to sliding on the members 20, 20.

Hinged to the hull of the vessel A at I6 there is provided a skeg I5 extending rearwardly of the propeller 6. The extending portion I5a of said skeg I5 is curved upward to provide protection to the propelling unit B, and particularly to propeller 6, when the vessel is moving ahead or astern over shoal regions. Said skeg I5 is V-shaped, its narrow end being curved up, as described, and the wide part being closed and hinged to the hull as at I6. Such construction enables the skeg I5 to withstand considerable side thrust and impact loads which occur when the unit B is turned through an angle, and a submerged obstacle, such as a rock, strikes the skeg I5 at an angle. The wider portion of said skeg I5 is preferably built up from channel steel and is covered, both top and bottom, with sheets 2I to form an enclosed member which prevents an accumulation of drift wood, weeds or the like, as would occur if an open or skeleton skeg were used. An inclined link I8 is hinged to the skeg I5 at its lower end as at I1, and at its upper endl 9is hinged to the connecting member I3, as at It will now be understood in view of the foregoing description that when the skeg I5 strikes a submerged obstacle, the same willv operate to raise said skeg I5 which, in turn, will raise with the aid of the inclined link I8, connecting member I3, and the brackets III, II and I2, the entire propelling unit B. When the obstacle is passed, the weight of the unit B, as well as that of the skeg I5, and of the brackets I0, II and I2, opcrates to lower the unit B and to bring it down to its original operative position. In shallow waters, the operation of the skeg I5 causes the propeller 5 to follow the configuration of the bottom at a safe distance therefrom, whereby maximum safe immersion of the propeller is effected at all times. Figs. 1 and 3 illustrate different draft conditions of the vessel, the dotted line d-d representing the loaded draft line, and the dotted line ee the light draft line. From the examination of said figures it is clear that when the propelling unit is in position shown by the solid lines, the immersion of the propeller 6 is insufficient for operation under the light draft line conditions. In accordance with the inven tion, operative position of the propelling unit B and consequently the immersion of the propeller 6 are made adjustable according to the draft conditions. The adjustments are effected in the present embodiment with the aid of a cable and counterweight mechanism which comprises a cable 23 passing over a number of suitable pulleys or drums, such as 24 and 25, having one of its ends fastened to the bracket III, while the other end has a counterweight 26 attached to it. Cable 23 is provided with suitable means operating to restrict adjustably its upward movement beyond a certain predetermined point, but permitting its free downward movement, or in other words, restricting the downward movement of the propelling unit B beyond its predetermined operative position and permitting free upward movement of said unit. In the preferred embodiment of the invention, said means are represented by a ratchet wheel mechanism provided in the drum 25. With the aid of the handle 25a the propelling unit B may be raised or lowered and adjustments of the operative position thereof. are thereby effected, since the ratchet mechanism provides a stop for the propelling unit in its downward movement. Referring to Figs. 1 and 3, by raising the counterweight 26 to the position shown in dotted lines, the propelling unit will be lowered to the position represented by similar dotted lines, thus effecting sufficient immersion of the propeller 6 for light draft line conditions. Of course, any intermediate position of the propelling unit between those shown by the solid and dotted lines in the Figs. 1 and 3 may be easily effected. The counterweight 26 is so selected that it will support part of the weight of the propelling unit and brackets, thus decreasing the force which must be applied to the skeg I5 for raising the unit B. However, the counterweight should not be so heavy as to cause rising of the propelling unit B in operation except where required to protect the propeller. In some instances I proposeto form the counterweight as a water tank, which can be varied in weight by pumping the water into or from said tank and so regulate within rather narrow limits the minimum forces required to raise the skeg and attached propulsion unit.

The electric motor 11 is supplied with current by a suitable generator I electrically connected to said motor with the aid of suitable conductors. The generator I is driven by a prime mover of any suitable type, as indicated at' 8. Any practical type of prime mover may be used for the above purpose, and any other source of electric current than a generating unit may be utilized, if practical. Such a generator and prime mover may be of the conventional Diesel power driven generator units now available for such uses.

In operation, the propelling unit B is first set at a predetermined proper elevation for the best operation in the given draft conditions. The drum 25 is used for this purpose, as described. The setting thus effected determines the maximum depth to which the propeller 6 will be permitted to descend, but it will not restrict or prevent the raising of the propelling unit B by the skeg I5 when the same strikes a submerged obstacle or is following the configuration of the bottom in shallow waters. The propelling unit 6 can be turned with the aid of a bar or tiller t either to the right or to the left, turning in supporting brackets, in order to steer and maneuver the vessel. When it is desired to raise the propelling unit for inspection or repair, hinge i9 is disengaged, and the propelling unit is simply slipped up on the frame structure. 4 Such raising may be done either by hand or with the aid of a suitable crane. It may also be done conveniently with the aid of the drum 25, in which case a suitable support of sumcient height with a pulley provided at its top is used in place of the pulley 24.

The modified structure shown in Figs. 3, 4 and is adapted for use in place of or as a substitute for the preferred structure. In said modified structure the power unit comprises a gasoline motor, such as the conventional outboard type shown at c, suspended in brackets I 0, ii and i2 similarly to the electric motor I) of the preferred structure. The ends Hlb, Hb

and HI) of the brackets l0, H and I2 are slid able on a member I 4 fastened to a substantially vertical link 3|. Said link 3! is hinged as at 32 to the skeg 35, and at 33 to the upper substantially horizontal link 36. Said link 36 is hinged to the hull of the vessel, as at 31. The skeg 35 is hinged to the hull of the vessel as at 35 and is bent upward in its part 35a and forward toward the vessel in its part 351), where it is fastened in any suitable manner to the link 3!. The wider portion of said skeg 35 is preferably made similar to that of the skeg l5 of the preferred structure, that is, the same is built up from channel steel and is covered, both top and bottom, with iron sheets, such as shown at 65. Such construction, in addition to limiting the accumulation of litter on the skeg, also imparts a buoyancy to the skeg which assists materially in reducing the amount of counterweight required to minimize the forces operating to raise the skeg and propulsion unit. The cable 23 is fastened to the link 3| near the middle portion thereof, as at 23a.

From the above description it will be clear that in the modified structure the thrust of the propeller 6 is transmitted to the hull of the vessel through the upper link 36 and the skeg 35, and that in said modified structure the frame members such as 20, 20, are entirely eliminated.

In order to strengthen the link 36 and the skeg 35, the same are made of relatively large transverse dimensions, particularly at the hinges 34 and 31 (see Fig. 4) in order to make the structure strong enough to withstand considerable side thrust when the propelling unit is turned to the right or the left to steer the vessel.

The cable 23 is passed over the pulleys 24 and 38, and the counterweight 26 is attached to its end. In this embodiment I prefer for the sake of economy to dispense with the drum such as 25 (see Fig. 2), substituting for the same the structure shown in Fig. 5. Said structure comprises an angular bracket 39 provided with longitudinal slots 39a and 39b. Bolts 40, 40, secured at a suitable place on the vessel structure engage the slot 39a and enable fixing the bracket 39 at a desired elevation. The cable 23 passes through the slot 3% and slides freely therein. A washer iii serves as a stop and prevents upward movement of the cable beyond the desired elevation, thus preventing the downward movement of the propelling unit C below the point for which the bracket 39 is set. In Fig. 3 there is shown in solid lines the operative position of the propelling unit C for the loaded draft line condition. To set the structure for the light draft line condition, such as shown by the line e-e, bolts 40, 40 are loosened, and the bracket 39 raised to a higher position, whereupon the bolts 49, 40 are tightened up. This position of the bracket 39 will permit higher upward movement of the counterweight 26 and will allow the propelling unit C to assume the position shown in Fig. 3 in dotted lines, insuring complete immersion of the propeller 6. Bracket 39 also operates to prevent excessive oscillation on the counterweight 26 under actual operating conditions. If desired, the counterweight 26 may be made slidable in vertical direction in side guides, thus entirely eliminating the possibility of objectionable oscillation. A certain amount of adjustment is possible, if desired, by moving the washer 4| on the cable 23. It should be noted that the axis of the propeller 6 is slightly rotated in the counter-clockwise direction as the propeller 6 moves down, which operates to set the propeller 6 in a more efiicient position for operation in shallow waters. The action of the skeg 35 and its cooperation'with the counterweight 26 are similar to those of the skeg I5 of the preferred structure. There is no sliding of the brackets l9, H and I2 on the member I during the operation. However, when it becomes necessary to raise or to remove the propelling unit C for inspection or repair, the same may be done without disassembling the entire structure by slipping the unit C upward relative to the member l4.

Tins, in one of its broader aspects, my invention contemplates providing a novel detachable propelling unit for surface water craft, which unit is capable of being attached to the hull of a water craft of any kind without making any irreparable modifications in the hull structure thereof, and which is further capable of being adjustably set during the operation in an operathis position to suit the draft characteristics of the particular water craft as well as the load conditions thereof, and which is provided with means operating to raise said propelling unit in order to make the propeller avoid submerged obstacles or prevent it from scraping the bottom when the craft is being operated in shallow waters.

Although only two embodiments of the present invention have been illustrated and described, numerous changes and modifications in the form and arrangement of parts will appear to those skilled in the art, and the same may be made without departing from the spirit of my invention. For example, direct mechanical drives such as belts, ropes, gears, chains, and the like, transmitting mechanical power directly to the vertical transmission shaft of the propeller, may be used. For example, in the construction shown in Fig. l, a prime mover such as a steam engine, or a stationary gasoline engine may be mounted adjacent the stern of the hull and be coupled with the vertical transmission shaft in any manner to permit relative vertical movement of the shaft to the prime mover, while being power driven by the prime mover. One such coupling device may be the use of drive pulleys on the shaft and on the prime mover and the connection thereof by a flexible driving belt or belts. In certain instances, a slip joint or spline may be provided in the transmission shaft between the propeller and the prime mover and so permit the raising and lowering of the propeller by a telescoping action within the shaft. Such an arrangement would be desirable'particularly'where the device of the present invention is utilized in a conversion of a vessel, as for example from a stern paddle wheel type to a propeller driven type of vessel.

Another type of prime mover which may be utilized is a steam or other power driven unit mounted directly above the transmission shaft and movable therewith and supplied with steam or other power from a power generating unit within the hull of the vessel. In place of the drum 25 or the bracket39, a simple loop on the cable 23 cooperating-with a number of hooks suitpositioned may be used for the purpose of adjusting the operative position of the propelling unit.

' I claim:

'1. A marine propulsion unit comprising a hinged frame vertically disposed to have its upper andlower members extending substantially horizontallyand an intermediate member extending substantially vertically, said frame at the front ends ofits horizontally extending members being adapted to be hinged to the hull of a vessel and to .be adjustably limited in its downward movement relative thereto; a power driven propeller unit rotatably secured to the intermediate member of said frame and bodily movable therewith, said unit including a screw propeller, a substantially vertical power transmission shaft therefor and an internal combustion engine of the outboard type operatively connected therewith; and a propeller protecting member extending beneath the propeller and secured to said intermediate frame member and adapted to move said frame in response .to its movements occasioned by obstructions of the channel.

2. A marine propulsion unit comprising a hinged frame vertically disposed and having its upper and lower members extending in a substantially horizontal plane and connected with a intermediate member lying in a substantially vertical plane, said frame being hinged at the forward ends of the horizontally extending members to the stern of a vessel and adjustably limited in its downward movement relative thereto; a power driven propeller unit rotatably secured to the intermediate member of said frame and bodily movable therewith, said unit including a screw propeller, a substantially vertical power transmission shaft therefor and an internal combustion engine of the outboard type operatively the channel.

connected therewith;- a counterbalance operatively connected to the intermediate member of said frame and adapted to facilitate the movement of said propeller unit relative to the vessel; and apropeller protecting member hinged to the hull at one of itsends and extending beneath the propeller and secured to said intermediate frame member at its other end, said protecting member being adapted to move said frame in response to movements occasioned by contact withobstructions in the channel.

8. A marine propulsion unit comprising a hinged frame vertically disposed to have its upper and lower members extending substantially horizontally and an intermediate member eX-;

tending substantially vertically, said frame at the frontends of its horizontally extending members being adapted to be hinged to the hullrof a vessel and to be adjustably limited in its downward movement relative thereto; a power driven pro-- peller secured to the intermediate member of said frame and bodily movable therewith; and a propeller protecting --member extending beneath the propeller andsecured to said intermediate frame member and adapted to move said frame in response to its movements occasioned by obstructions'of the channel.

4. A marine ropulsion unit comprising a hinged frame vertically disposed and having its upper and lower members extending in a sub- ''stantially horizontal plane and connected with an intermediate member lying in a substantially vertical plane, said frame being hinged at the forward ends of the horizontally extending members to the stern .of :a vessel and adjustably limited in its down-wardmovement relative thereto; a power'drivenpropellersecured to the intermediate member of said frame and bodily movable therewith; -a counterbalanceoperatively connect 'ed to the intermediate member of said frame and adapted to facilitate the movement of said propeller unit relative to the vessel; and a propeller protecting member hinged to the hull at one of its ends and extending beneath the propeller and secured to said intermediate frame member at its other end, said protecting member being adapted to move said frame in response to movements occasioned by contact with obstructions in HAROLD w. MILLER. 

